


Show Me Off

by ithilien22



Category: Shadowhunters (TV)
Genre: Alec Lightwood & Jace Wayland Friendship, Anal Sex, Bottom Alec, Exhibitionism, M/M, Miscommunication, Rough Oral Sex
Language: English
Status: Completed
Published: 2016-06-02
Updated: 2016-06-02
Packaged: 2018-07-11 21:22:05
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 4,105
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/7070869
Author URL: https://archiveofourown.org/users/ithilien22/pseuds/ithilien22
Summary: <blockquote class="userstuff">
              <p>Alec accidentally discovers a new kink, Magnus mistakenly assumes that Alec is still in love with Jace, and Jace resolves to start knocking before he enters a room.</p>
            </blockquote>





	Show Me Off

**Author's Note:**

> This was written for a tumblr prompt: _Could you make a 'everyone keeps walking in on Malec' fic? Cuz I need more bottom/cockslut Alec in my life tbh_
> 
> It's only Jace that walks in on them in this fic, but there's plenty of 'bottom/cockslut Alec' so hopefully it still fits the bill. There are also a bunch of feelings and awkward conversations and miscommunications in between the smut bookends, so if you're just here for the porn you can skip the middle parts, lol.

Alec has been so desperate from the moment Magnus walked into the institute, it's a miracle he manages to make it through the briefing. They haven't seen each other in _two weeks_ and Magnus looks more gorgeous than ever, with light purple streaks in his hair and the hard lines of his muscles just visible through the delicate material of his shirt. Alec doesn't even remember half of what is said during the meeting, and he knows that's completely unprofessional, but he feels like he lost all rational thought the moment he saw Magnus. He just _wants_.

So the second everyone else leaves the institute library (used in lieu of the usual briefing room due to several ancient texts they needed to review), he practically throws himself at Magnus, latching onto his neck without so much as a proper 'hello'.

Magnus doesn't seem to mind too terribly though. He just chuckles lowly and bares his neck a bit more to give Alec easier access as he continues his assault.

"I missed you too, Alexander," he says fondly. 

"Magnus," Alec gasps out, angling back up to kiss him properly, "by the angel, I missed you."

Magnus kisses him back with equal fervor, but somehow seems to remain much more calm and levelheaded than Alec feels.

"I know we can't get too carried away here in the institute," Magnus says in between their heated kisses, "but I do hope you're spending the night at the loft, because I definitely have _plans_ for you tonight, my dear." 

Alec whimpers and clutches at Magnus's shirt. 

"I don't care where we are, I can't wait, Magnus please," he begs, and Magnus's eyes flicker gold. 

"Last night wasn't enough for you, darling?" Magnus asks, tangling one of his hands in the hair at the base of Alec's neck. 

Last night had been... fantastic (and new and exciting and nerve-wracking). But they'd still been apart. It hadn't been _Magnus_ inside of him.

"Need you," Alec groans in response, trying to slot their hips closer together. 

"I know what you need," Magnus tells him, voice low and rough.

Before he can respond, Alec feels Magnus pull back and then suddenly he's being spun around and shoved up against the nearby desk, Magnus crowding in behind him and reaching to undo the button on his jeans. Alec immediately moves to help him, shoving his pants and boxers down as quickly as possible and sighing in relief when he feels the kiss of magic slicking him from inside. 

He groans in frustration though when he feels Magnus tentatively press a finger inside. That's not what he wants right now - he's way too far gone.

"I don't need that, Magnus please," he says, pushing his hips back to meet the too-light pressure of Magnus's finger despite his words. "Come on, fuck me."

Magnus practically growls and bites at Alec's shoulder through his shirt as he removes his finger and replaces it with the blunt head of his cock.

"Is this what you want, angel?" he asks, the softness of his words not quite matching his low and desperate tone. "Is this what you were missing when I was gone?"

"Yes, yes, yes," Alec breathes out as Magnus pushes in, folding Alec forward across the surface of the desk. 

"So beautiful, Alexander," Magnus murmurs into Alec's neck, snapping his hips at the perfect angle. "Always so good for me."

Alec closes his eyes, a serenity that he hasn't felt in weeks finally washing over him again. It's such a relief to feel Magnus against him, whispering endearments into his skin and fucking into him so perfectly. He honestly doesn't know how he lived without this feeling before he met Magnus.

He's almost completely lost in the sensation when a sudden soft noise pulls him back. The desk he's currently bent over faces the door to the library, so Alec has a perfect view as it starts to open. His breath catches and he clenches around Magnus, still buried inside him.

"Alec? Are you still in here, I-"

Alec looks up just in time to lock eyes with a stunned Jace, and then he's coming harder than he ever has in his life, cock completely untouched.

_Well, fuck._

\---

Alec just stands frozen where he is, leaning forward against the desk, for several long moments after the door shuts behind Jace's quick retreat. Magnus hasn't moved either, though Alec can feel him breathing heavily against him, his cock starting to grow soft inside Alec the longer the moment stretches out.

"Alec," Magnus says eventually, his voice heavy and tense. He starts to pull back and Alec panics, reaching back to hold him in place, desperate to fix it somehow. He pushes his hips back and Magnus groans, but then he stills Alec with firm hands and pulls back completely, slipping out and away. 

Alec feels suddenly empty and beyond embarrassed. Magnus's tone was warning enough; Alec knows instinctively that he doesn't want to see the look on his face right now. He straightens up slowly and moves to pull his pants up but hesitates at the mess he's made until it's suddenly gone in a pulse of magic.

Alec buttons his jeans and turns around slowly, still not quite meeting Magnus's gaze.

"Thanks," he whispers in response to the magic. He's sure his face must be beet red.

"I should go," Magnus says, and Alec finally looks up at him. He looks completely put together, no hint at all of what they were just doing, except the way he's fidgeting with his hands like he does when he's nervous. Alec's stomach drops.

He doesn't know how he would have expected Magnus to react to a situation like this - with an inappropriate joke, maybe? - but definitely not like this. Now that Alec is finally looking at him, he can see that Magnus is the one not returning his gaze.

Alec feels a deep pool of shame well up inside his chest. 

"I'm sorry," he says. "I didn't mean to- I. I didn't know that I..."

But Magnus is shaking his head, smiling in the fake way that he sometimes does around other people, but not Alec.

"It's fine, darling," he says, voice too light. "I just need to get going."

He's already moving around Alec to open a portal against the wall, and Alec suddenly feels anxious that he's not coming back.

"Magnus," he tries, but he's already stepping through the portal, letting it wink out of existence behind him.

\---

When Alec stands outside of Jace's door several hours later, he hesitates, debating with himself, but eventually he raises a hand and knocks. There's no immediate response though, so he takes a deep breath and pushes the door open, finding Jace lounging on his bed with a book open in front of him. He sits up and sets it aside when he sees Alec in the doorway.

"Since when do we knock?" Jace asks with a grin, seemingly without thinking, but as his words catch up with him his smile falls slightly and his cheeks flush.

Alec coughs.

"I thought maybe we should pick up the habit," Alec says awkwardly.

"Yeah," Jace agrees. "That's probably... yeah."

Alec hovers in the doorway, not sure how to start a conversation that he doesn't actually want to have in the first place.

When he finally opens his mouth again, he and Jace both start at the same time.

"I'm sorr-" "I'm sorry-"

They both cut off when the other starts to speak and Jace gives a nervous chuckle before nodding at Alec in a _go ahead_ gesture.

"That won't happen again," Alec says. At Jace's raised eyebrow, he rolls his eyes and clarifies, "at the institute, I mean. We never should have - I. I just really..."

He trails off, blushing, and clears his throat.

"Anyway, I just wanted to tell you that," he says. Then, in a rush- "and please, please don't tell Izzy."

Jace smirks outright at that, and warning bells start to go off in Alec's head.

"I don't know," Jace muses, still grinning evilly, "I mean, this is a big moment to take away from her - she and I have been waiting for you to get laid for a long time, Alec. A _long_ time."

"Haha, very funny," Alec responds sarcastically, adding a rude gesture for good measure, but Jace just laughs, longer and harder than Alec thinks is really warranted. After a moment his expression turns thoughtful though, and somehow that's even more concerning to Alec.

For good reason, apparently, as the next words out of Jace's mouth are, "so... was it like his turn or something? Is that why you were... you know?"

It takes Alec's brain a few moments to catch up to the innuendo of Jace's question, but when he does, he groans aloud.

"By the angel, Jace. Do we actually have to talk about this?"

"Do you know how long I've been waiting to talk to you about sex, Alec?" Jace asks rhetorically, then immediately tells him, "Since I was thirteen and that mundane girl let me touch her breasts. I'm sorry, but this is all we're going to talk about now. We have literally _years_ to make up for here."

Alec scowls back at him.

"You already told me all about that girl," he reminds Jace, "and all the other ones, too."

Alec remembers every detail about that first girl, in fact, because it was all he had thought about for weeks after - constantly turning it around in his brain and trying to figure out why it made his gut clench whenever he thought of Jace with her.

He realizes though, talking about it now, that even the memory of that feeling has mostly faded. Looking at Jace in this moment, all he feels is exasperation laced with a terrible fondness. 

"Yes, but it was like talking to a brick wall before," Jace tells him. "Now we can actually swap stories."

He waits Alec out for a few seconds and then gives him a look. 

"Come on, answer my question!" he prompts.

Alec sighs deeply. On the other hand, maybe he's not actually all that terribly fond of Jace in this moment.

"Fine. I'm usually... I. That's how- how we. I'm- that's usually how it is," he mutters finally, crossing his arms protectively.

"Really?" Jace asks. He looks genuinely surprised. "I never would've guessed that."

"I'm gay, Jace," Alec bites out in response.

He sees the corners of Jace's mouth tilt up and Alec finds himself wondering if he's ever actually said that out loud before.

"I know that," Jace says. "I guess I just thought it was the other way around though? Because you're... you know. And Magnus is..."

He trails off, gesturing vaguely. Alec feels offended, but he's not sure if it's for himself or for Magnus. _Both_ , he decides.

"You're an idiot," he settles for saying, because anything else he can come up with requires actually acknowledging what Jace is talking about.

Jace holds his hands up in a gesture of surrender, "OK, I'm an idiot. How am I supposed to know this stuff? I don't know how it works."

Alec continues to scowl, but it's apparently not enough to deter Jace because he asks, "So is it good then? Being the one who gets f-"

"By the angel!" Alec cuts him off, cheeks flaming in embarrassment.

"What? I'm just asking!" Jace says. He's clearly enjoying this conversation way too much. It's almost enough to make Alec wish it had been Izzy instead. He grimaces at the thought. _Almost_.

"Yes, it's good, OK?" Alec finally snaps. "It's fucking great and I was so fucking desperate for it that I couldn't even wait to go back to his place later tonight and that's exactly why you and I ended up here, having the worst conversation of my entire life."

He takes a deep breath and feels slightly victorious at Jace's dazed expression.

"So can we be done talking about this now?" he asks.

Jace's smirk comes back full force and Alec has to resist the urge to knock it off his face.

"You did, you know, clean up after yourselves, right?" Jace asks, full of mock concern. "There's another meeting in there later today."

"Fuck you," Alec replies charmingly, but without any real heat behind it. 

He's already turning to leave when Jace says, "no, fuck _you_ , apparently," and then cackles madly at his own pun.

Alec rolls his eyes, but doesn't stop walking. He's partway down the hall, Jace's laughter still following him, when he feels his phone vibrate with a new message.

 _From: Magnus_  
_I'm sorry for leaving like that. Will you come over later when you're free?_  


Alec's heart clenches and he immediately types out a response.

 _To: Magnus_  
_On my way._  


\---

Standing outside of the door to the loft, Alec has a sense of deja vu. He has a key, but he doesn't feel like he should use it now, so he just hovers awkwardly right outside. Before he can make up his mind though, the door opens to reveal Magnus waiting for him.

"Alexander," Magnus greets him warmly, but his smile doesn't quite seem to reach his eyes. He doesn't move to kiss him, like he normally would, but instead just steps aside to allow Alec to pass by.

They both sit down on the couch, but again, with more space between them then there normally would be. Magnus angles his knees towards Alec though, and Alec finds himself pathetically hoping that's a good sign.

"I'm sorry about how I acted before," Magnus tells him. He sounds more sincere than he had earlier, but still more guarded than usual. "I know this isn't something you can control. You can't always help how you feel."

Alec feels like he could die of embarrassment. Of the two of them, Magnus has decidedly more sexual experience, so Alec has always looked to his boyfriend to help him understand any new desires he feels as they've slowly been exploring their relationship together. It's always a little embarrassing regardless, but it's never been like this. Magnus has always been supportive, before.

"I didn't _know_ ," Alec tries to explain. "Really. I never- I didn't know I would react like that."

Magnus's forehead wrinkles and he gives Alec an almost incredulous look.

"Are you just lying to me, or are you actually lying to yourself about this?" he asks, and Alec feels like he's been punched in the gut. 

"I'm... I'm not-" Alec stutters out, but Magnus continues.

"I've known how you felt about him since the day we met, Alexander, remember?" he says tensely.

Alec hears the words Magnus is saying, but he can't make any sense out of them. 

"How I felt about who?" Alec asks finally, feeling completely out of his depth.

"Jace," Magnus answers tightly, and Alec blanches. _What?_

"Jace?" Alec repeats. "I don't- there's not. I don't have feelings for Jace, Magnus."

Magnus scoffs and starts to look almost angry.

"I think we're a little past that point now, Alec," he says. "I felt your reaction to him."

Alec can't tell if he wants to laugh or cry at the absurdity of that statement, and it finally hits him that they've been having two entirely different conversations.

"By the angel, Magnus," Alec says, some of his frustration seeping into his words. "That wasn't about _Jace_. He just happened to be the one who- he was... he was just there."

Now Magnus is the one who looks lost. "What?"

"That wasn't about Jace," Alec repeats. "It was about _you_. Having somebody, _anybody_ see you, _us_... like that. Someone seeing the way you... I- I didn't know it would... but I. It-"

Magnus's expression slowly clears as Alec tries to explain, until eventually he's smiling. It's his real smile this time, though it's twisted to be a bit self-deprecating.

"Oh, I'm an idiot," Magnus says, reaching out and cupping a hand against Alec's cheek, "and you'd think I would've outgrown something as petty as jealousy by this point."

"I'm not going to pretend I never had feelings for Jace, but it's not there anymore," Alec insists. Now that they're finally talking about the same thing, Alec realizes that they probably should have talked about this sooner. "It hasn't been like that for a long time, Magnus."

"I'm sorry I assumed," Magnus says softly, still stroking Alec's cheek. "I can't imagine how badly I must have made you feel about what happened. I'm so sorry."

"'s ok," Alec says, closing his eyes and leaning into Magnus's touch. "Jace is going to make fun of me until the day he dies though."

Magnus laughs, moving his hand up from Alec's cheek to tangle in his hair. 

"Maybe I can find another memory demon," he muses, and Alec smiles.

\---

Alec startles awake to find that he drifted off in Magnus's lap on the couch, sometime during their conversation. Magnus's fingers are dancing idly along his scalp and he's humming softly.

"Sorry," Alec says, sitting up slowly. "I didn't mean to fall asleep on you."

"Quite alright, darling," Magnus tells him. "You had a stressful day, and I know I didn't help much."

"You helped plenty," Alec replies, leaning in for a kiss. He smirks and adds playfully, "If I remember, I think I was the one that didn't get a chance to help _you_ out."

Magnus hums in approval. 

"Is that an offer?" he asks, but Alec's hand is already on the button of his jeans, so he decides it's rhetorical.

Alec has just lowered the zipper on Magnus's jeans and is tugging at Magnus to sit up so he can get them properly off when Magnus pulls back with a familiar glint in his eye.

"Wait, not here," he says, standing from the couch and pulling Alec along with him. Alec assumes at first that they're just moving to the bedroom, but they keep going - through the bedroom and out onto the balcony.

It's late now and Magnus's loft is several stories up from the street, but it's a clear night, with lit streetlights illuminating them softly. Alec shivers.

"Magnus, what-" he tries to ask, but Magnus shushes him, leaning back against one of the side railings. He pushes his pants down to his thighs, freeing his cock to jut up against his stomach. Alec's mouth waters.

"On your knees, angel," Magnus tells him, and Alec immediately moves to comply.

Once Magnus's cock is in front of him, he leans forward and licks gently down the length, smiling when he feels Magnus's hands tangle in his hair. He lets Magnus guide him down to mouth at his balls and just below, and then back up to lick at his cock again. Magnus groans deeply and Alec takes it as a sign to pull the head into his mouth and suck at it gently.

"Fuck, Alexander," Magnus pants. His grip tightens in Alec's hair and Alec opens his mouth, just letting Magnus's cock rest against his tongue, until Magnus starts to thrust forward.

"So good for me," Magnus says, gently working his cock back into Alec's throat as Alec hums around him. He trails off into a groan, and his voice is unsteady when he adds, "and now anyone could look up and see you like this, Alexander. There's a couple coming out of the building across the street right now, and all they would have to do is look up and they would see you. They would see how perfectly you're taking my cock. How badly you want it."

Alec whimpers around Magnus and has to pull off for a second to catch his breath, he's so overwhelmed. He presses a kiss to the inside of Magnus's thigh in apology and chances a glance at the street below. Magnus is right; there are people right below them.

Alec usually hates feeling exposed, in any context, which is why the shock of lust takes him by such surprise. But Magnus makes him feel so beautiful, so special. He thinks maybe it's about wanting other people to see him the way Magnus sees him. Or maybe he just wants to see himself that way.

His own cock his aching in his jeans, and he quickly pulls it free before swallowing Magnus back down again. He doesn't move to stroke himself though, he's already dangerously close just from the thought of what they're doing.

"I wish everyone could see you like this," Magnus unknowingly echoes Alec's thoughts, petting almost distractedly at Alec's hair now, as he allows Alec to set the pace. Alec takes him all the way in and then works his throat, swallowing around him. Magnus whines low and broken but is still firm in pulling Alec back after a moment, letting him gasp a breath against his thigh.

"You think I didn't see how distracted you were this morning, during the briefing?" Magnus asks, rubbing his cock against Alec's cheek as Alec catches his breath. "Were you thinking about my cock then too?"

Alec nods against Magnus's skin, not trusting his voice. He glances down at the street again; there are different people now, a group of women. He thinks he sees one of them glance up.

He surges up to his feet without warning, just needing to kiss Magnus, and Magnus kisses him back with just as much feeling. Magnus's tongue fucks into his mouth and his hand wraps around Alec's cock and Alec is _done_. He whimpers into Magnus's mouth as he suddenly spills across his hand.

"Sorry, sorry, I couldn't-" he says, but Magnus quiets him with a kiss, still stroking him through it. Alec is shaking. 

Magnus carefully pulls his own pants back up but doesn't bother to fasten them, and gently guides them both back inside, into the bedroom. They fall together onto the bed and Alec kisses Magnus's neck, his adam's apple, his collarbone, anywhere a sliver of skin is exposed from the shirt he's still wearing. He reaches down and pulls Magnus's cock back out, still slick from Alec's own mouth, and starts stroking him fast and rough. 

Magnus reaches down to help him, changing the pace just slightly, and it doesn't take long until he's shooting across their joined hands, biting softly at the skin under Alec's ear. 

After a moment, Magnus cleans them both with his magic and finally gets rid of their clothes in the process, settling back more comfortably into the bed and pulling a blanket up to cover them. Alec snuggles into his boyfriend's side and feels a light kiss pressed into his temple.

"Well, that was certainly a better ending than I thought this day would have," Magnus murmurs against him. 

Alec feels himself tense slightly, doubt creeping back in.

"You don't think it's... weird?" he asks softly. Magnus's arm tightens around him.

"I think everything about you is incredibly sexy, Alexander," Magnus responds with feeling, "and I'm so sorry I gave you reason to think otherwise today."

"It wasn't your fault," Alec tells him. He's the one who can't talk about this stuff without stuttering through it, but Magnus is still always so patient with him. He doesn't know how he got so lucky. 

Magnus hums something that sounds like disagreement, but he doesn't respond directly, just softly cards a hand through Alec's hair.

Then after a moment, he asks, "How did it feel this time?"

"Really good," Alec answers. He's blushing again, but determined to talk to Magnus since not talking about things landed him in enough trouble for one day. "It was better with the- um, since it was just random people who don't know us, and I don't even know if they saw anything. It's uh. it's less embarrassing."

Magnus chuckles.

"Do I want to know what Jace said?" he asks, but Alec is already shaking his head before Magnus even finishes asking the question.

"No, you definitely do not," he replies quickly. 

They're both quiet for a moment and Alec feels himself starting to drift off. 

"You know the real lesson here, right?" he asks Magnus sleepily.

"What's that, darling?" Magnus returns softly.

"Don't leave me for so long again," Alec says, and he means for it to be playful but it comes out sounding kind of pathetic even to his own ears.

Magnus pulls Alec closer, and Alec's eyes flutter closed without his permission.

"I love you, Alexander," Magnus whispers tenderly, and all of the hurt and miscommunication of the day seems to wash away with those simple words.

Alec falls asleep still smiling.

**Author's Note:**

> Come prompt me on [tumblr](https://ithilien-writes.tumblr.com/)!


End file.
